@RequestMapping("/attachImage.do")
public void attachImage(RMap rmap, ModelMap model, HttpServletRequest request, HttpServletResponse response) throws IOException {
    // 파일 조회
    UMap umap = commonService.selectAttachFile(rmap, model);

    byte[] data = (byte[]) umap.get("file");
    String file_type = (String)umap.get("file_type");
    
    if (data == null || !file_type.equals("0001")){
        String thumbnail = (String) umap.get("thumbnail");
        data = Base64.decodeBase64(thumbnail.split("base64,")[1]);
    }

    // 이미지를 전송한다.
    response.setContentType("image/jpeg");
    response.getOutputStream().write(data);
}